Figure 6
Representative photomicrographs showing distribution and delivery of intranasally administered mitochondria labeled with bromodeoxyuridine (BrdU) via the rostral migratory stream (RMS). (A) Anti-BrdU antibody followed with horseradish peroxidase allowed tracking of allogeneic mitochondria (brown color) in different brain regions of the olfactory bulb glomerular layer (GL), accessory olfactory lobe (AOB), corpus callosum (CC) and striatum (ST), represented as rectangular high-power fields in the sagittal sections of mouse brains. Nuclei were counterstained with Meyers's hematoxylin (blue dots). Arrows indicate BrdU-positive signals in high-magnification fields. BrdU-labelled mitochondria are obvious in the ST (third panel) and CC in zoomed images (second panel). Intranasally administered mitochondria penetrated to the AOB (first panel), but not to the bulb glomerular layer (GL) of the outer tissue layer of the olfactory bulb (fourth panel), and progressed into the RMS (third panel). (B) Expression of BrdU signals in the RMS and ST at higher magnification. (C) Double immuofluorescent staining with doublecortin (DCX) and BrdU antibodies confirmed the uptake of exogenous mitochondria (red color) in DCX-positive migrating neurons of the RMS (green color) around the AOB / ST-CC interface, indicated with a rectangle. (D) Co-localization of images was captured in double-labeled sections in single optical sections of z-stack confocal images, presented as side views of the x–z and y–z planes. *P < 0.05, vs. Sham, WT wild-type controls, Mito mitochondrial alone, P-Mito Pep-1-labelled mitochondria, OB olfactory lobe, EPC external plexiform cells, MCL mitral cells.
